Ms Mukherji says they have invited several leading intellectuals and cultural figures of Bengal who back their campaign.
Hundreds of prostitutes from across South Asia have assembled in Calcutta to attend a conference that seeks to press for the legalisation of the sex trade.
The union, with a membership of more than 5,000 active sex workers, has been at the forefront of a movement seeking to legalise the trade.
It is led by a fiery middle-aged prostitute, Sadhana Mukherji, who says she was forced into the trade by greedy relatives after her father's death.
The union has been trying to organise sex workers in the region for some time now.
Support
The two-day conference has brought together more than 200 representatives of various sex workers' unions from cities across South Asia.
Ms Mukherji says they have invited several leading intellectuals and cultural figures of Bengal who back their campaign.
Many politicians belonging to different parties have also offered their support.
Ms Mukherji says the conference will decide on the future course of the movement in the region.
It will also frame lobbying strategies for furthering their cause.
Legalisation
Legalising the sex trade is being sought to protect the prostitutes from pimps, criminals and bribe-seeking policemen.
The sex workers are often under pressure to pay up or face imprisonment under various anti-prostitution laws effective in South Asia.
But Calcutta's deputy police chief, Sujoy Chakrabarty, says legalising the sex trade would lead to a rush of minors into the profession.
There would be no legal measure left to counter it, he said.
That view has been also supported by many politicians, journalists and social workers.